Prototype objects never share their map, and hence cannot be in deprecated state.

src/objects.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <sstream>
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/allocation-site-scopes.h"
@@ skipping 2913 matching lines @@
       map = ReconfigureProperty(map, i, kData, details.attributes(),
                                 Representation::Tagged(),
                                 HeapType::Any(map->GetIsolate()), FORCE_FIELD);
     }
   }
   return map;
 }
 
 
 // static
-MaybeHandle<Map> Map::TryUpdate(Handle<Map> map) {
-  Handle<Map> proto_map(map);
-  while (proto_map->prototype()->IsJSObject()) {
-    Handle<JSObject> holder(JSObject::cast(proto_map->prototype()));
-    proto_map = Handle<Map>(holder->map());
-    if (proto_map->is_deprecated() && JSObject::TryMigrateInstance(holder)) {
-      proto_map = Handle<Map>(holder->map());
-    }
-  }
-  return TryUpdateInternal(map);
-}
-
-
-// static
-Handle<Map> Map::Update(Handle<Map> map) {
-  if (!map->is_deprecated()) return map;
-  return ReconfigureProperty(map, -1, kData, NONE, Representation::None(),
-                             HeapType::None(map->GetIsolate()),
-                             ALLOW_IN_DESCRIPTOR);
-}
-
-
-// static
-MaybeHandle<Map> Map::TryUpdateInternal(Handle<Map> old_map) {
+MaybeHandle<Map> Map::TryUpdate(Handle<Map> old_map) {
   DisallowHeapAllocation no_allocation;
   DisallowDeoptimization no_deoptimization(old_map->GetIsolate());
 
   if (!old_map->is_deprecated()) return old_map;
 
   // Check the state of the root map.
   Map* root_map = old_map->FindRootMap();
   if (!old_map->EquivalentToForTransition(root_map)) return MaybeHandle<Map>();
   int root_nof = root_map->NumberOfOwnDescriptors();
 
@@ skipping 43 matching lines @@
           return MaybeHandle<Map>();
         }
         break;
     }
   }
   if (new_map->NumberOfOwnDescriptors() != old_nof) return MaybeHandle<Map>();
   return handle(new_map);
 }
 
 
+// static
+Handle<Map> Map::Update(Handle<Map> map) {
+  if (!map->is_deprecated()) return map;
+  return ReconfigureProperty(map, -1, kData, NONE, Representation::None(),
+                             HeapType::None(map->GetIsolate()),
+                             ALLOW_IN_DESCRIPTOR);
+}
+
+
 MaybeHandle<Object> JSObject::SetPropertyWithInterceptor(LookupIterator* it,
                                                          Handle<Object> value) {
   Handle<Name> name = it->name();
   Handle<JSObject> holder = it->GetHolder<JSObject>();
   Handle<InterceptorInfo> interceptor(holder->GetNamedInterceptor());
   if (interceptor->setter()->IsUndefined() ||
       (name->IsSymbol() && !interceptor->can_intercept_symbols())) {
     return MaybeHandle<Object>();
   }
 
@@ skipping 14313 matching lines @@
                                                CompilationInfo* info) {
   Handle<DependentCode> codes = DependentCode::InsertCompilationInfo(
       handle(cell->dependent_code(), info->isolate()),
       DependentCode::kPropertyCellChangedGroup, info->object_wrapper());
   if (*codes != cell->dependent_code()) cell->set_dependent_code(*codes);
   info->dependencies(DependentCode::kPropertyCellChangedGroup)->Add(
       cell, info->zone());
 }
 
 } }  // namespace v8::internal